Physiological and growth responses of young tomato seedlings to drip-irrigation containing two low doses of the arbuscular mycorrhizal fungus Glomus iranicum var. tenuihypharum sp nova

摘要

Two different doses of an arbuscular mycorrhizal fungus (AMF; Glomus iranicum var. tenuihypharum sp. nova) were applied through a drip irrigation system to evaluate their effects on the physiological, nutritional, and agronomic performance of tomato plants. Trials were conducted in south-eastern Spain under controlled greenhouse conditions from September - December 2012. The high rate of AMP colonisation at both doses applied improved plant growth performance, leading to significant increases in leaf macro- (N, P, K, Ca and Mg) and micro- (Fe, Cu, Zn, Mn and B) nutrient concentrations. The AMF present in colonised plants not only exerted some control over the rate of transpiration (stomatal control), but also maintained a higher rate of net photosynthesis and hence improved the intrinsic water use efficiency (computed from the ratio of the rate of net photosynthesis:stomatal conductance). In addition, a close relationship was found between the respiratory activity of the AMF and the rate of net photosynthesis, leaf N, P, Fe, and K concentrations, and fruit yield (expressed as the product of the average number of fruit x the average fruit weight in each treatment). In summary, the application of AMF was effective at improving the performance (i.e., the growth, nutrition, and yield) of tomato plants cultivated under an intensive fertigation regime